<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>三行两列布局</title>
    <style>
        #outside{
            border-left: 12px #ff46a3 dashed;
            width: 600px;
            height: 500px;
        }
        #container {
            margin:12px 12px;
            width: 500px;
            height: 200px;
            background-color: #77965b;
            border: 12px red dashed;
            padding: 12px 12px;
        }

        #test {
            width: 100%;
            height: 100%;
            background-color: #967c30;
        }
    </style>
</head>
<body>
<div id="outside">
    <div id="container">
        <div id="test"></div>
    </div>
</div>
</body>
</html>